


let's make a promise

by Hxstia



Series: Sweet Buns & Crest Babies [1]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: A lot more fluff tbh, Angst, F/M, Hot Mess Sylvain Jose Gautier, Hurt/Comfort, Mercie knows but she'd rather him figure it out himself, Spoilers for Azure Moon, Sylvain Jose Gautier Being An Idiot, Sylvain adores Mercie and his two remaining braincells refuse to put together why, There's A Tag For That, basically my refusal to succumb to the drought, they talk about feelings and war, they're both traumatised ok sylvain isn't the only one with issues
Language: English
Status: Completed
Published: 2020-02-22
Updated: 2020-02-22
Packaged: 2021-02-28 06:01:59
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,501
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22799011
Author URL: https://archiveofourown.org/users/Hxstia/pseuds/Hxstia
Summary: Sylvain roams the monastery restlessly on the eve of the invasion on Enbarr and stumbles upon a familiar face that wears a slightly less familiar expression. He doesn't like the look of it on her.or: Sylvain Jose Gautier being a hot mess for 3000 words
Relationships: Sylvain Jose Gautier/Mercedes von Martritz
Series: Sweet Buns & Crest Babies [1]
Series URL: https://archiveofourown.org/series/1655635
Comments: 8
Kudos: 58





	let's make a promise

**Author's Note:**

> Basically this is me refusing to let the Sylvain/Mercedes tag run dry and if I have to SINGLEHANDEDLY SPEARHEAD THE AGENDA I WILL  
> Also I feel like amongst all those talks of war and casualties between dimileth some should have gone to Mercie since she's literally the healer and a pacifist there has GOT to be some trauma in there some where. Mercie best girl I take no constructive criticism.

The air was chilly under the Blue Sea Moon, and Sylvain wondered, not for the first time that night, what in the goddesses’ name he was doing wandering the war-torn halls of the cathedral. He hadn’t been a frequent visitor in his academy days, save a few mandatory choir practices, and yet here he was- drawn from his slumber as he ambled towards the cathedral in a restless shuffle.

He usually slept like the dead after a battle- only to be assaulted by scarred faces and corpses in his dreams- and yet on this particular night slumber seemed to escape him. It had nothing to do with exhaustion, because he was plenty exhausted- Fort Merceus was hard conquered- and yet even as his eyelids drooped his feet carried him to the cathedral.

Sylvain sighed, fingertips tracing the stone walls of the hallways as he arrived at the cathedral’s entrance. His breath left in a puff of vapour and he watched as it evaporated in the midnight air before a low murmur startled him from his hazy reverie. Instantly, flames crackled at his fingertips as he went into high alert. He silently cursed at his negligence for leaving his lance in his quarters. Worse yet, he had no armour. If an intruder had really infiltrated the monastery, he’d be at a significant disadvantage. 

Also, Felix and Ingrid would never let him live it down if he died in his nightclothes.

Holding his breath, he crept past the pillars, peering silently over the pews at the lone figure seated in the first row. He let out an involuntary sigh of relief as he let his flames sputter out and die. Bathed in the moonlight that spilled from the arching stained glass windows was a familiar silhouette clad simply in a shawl and a nightdress, hands clasped together and lips moving in soft prayer. 

“Mercedes?” He asked quietly into the night, but the name rang through the empty cathedral startlingly loud and the woman in question flinched.

“Emile?” came a hopeful whisper and oh, did Sylvain’s heart sink.

Trying for a smile, he stepped out from behind the pillar and into the moonlight. He approached carefully, and with each step he saw the disappointment fill her pretty cerulean eyes… and the relief.

“Oh, Sylvain,” she said pleasantly though her shoulders had drooped at the sight of him, “what brings you here tonight?”

_ “I don’t know” _ is what he meant to say, instead what left his lips was “You.”

Sylvain felt heat crawling up his neck, because no, that was absolutely not what he had meant to say!  _ We don’t flirt with women in mourning, you absolute buffoon! _ He internally screamed as he resisted the urge to rub the back of his neck, a nervous tick of his that Mercedes absolutely knew about. 

As he sputtered to come up with an easygoing one liner to iron out his pathetic failure, a soft laugh drew him from his stunned stupor. 

“It’s nice to see war has yet to curb your philandering ways.” She tittered from behind her palm.

He managed a nervous laugh and a wincing sort of smile, “No well- I wasn’t trying to upset you- I just-“

Mercedes shook her head, tilting it back to give him an amused smile, “I’m teasing you, Sylvain.”

The laugh tore from his throat easier this time at her simple admission. “Well haha, then. I see you do have a bit of a mean streak after all! And yet, it only adds to your charm,” Sylvain stroked his chin in mock thought, “maybe you could give Felix some pointers?”

Her smile remained intact, but her eyes were tired in a way sleep could not remedy. “Perhaps,” she agreed not unpleasantly, but the look in her gaze said she was far away and Sylvain wasn’t quite sure he could reach her.

Again, all he could do was try for a suave smile, “And what is a lovely woman like you doing here at this hour, scandalously dressed? Am I interrupting a late night rendezvous?”

His efforts earn him a light swat to the arm, and he lets out a beleaguered yelp at her shocking display of violence. “Mercedes! Clearly you’ve been spending far too much time with Ingrid- agh, the agony!” he moaned, clutching his arm as he doubled over, “bested by a beautiful woman in her nightgown, what a wonderful way to die.” 

Amidst his dramatics, he peeked out of the corner of his eye to see her eyes wide and lips parted in shock. Slowly, they twisted into a grin as laughter burst forth, unlike her usual demure giggles or polite titters, that he observed with a triumphant grin was much more genuine. A pleasant warmth settled in his stomach at the sound, and he wasn’t quite sure whether that was a good thing or not, but if she kept laughing like that he found that he couldn’t quite bring himself to care.

“Oh, you silly man,” she gasped out between hiccups of laughter, “have you ever considered renouncing your title for a humble life as an actor?”

Sylvain straightened up with a cheeky wink, “Well I certainly have the looks for it.” 

“And the theatrics to boot.” Her laughter fading softly as she panted lightly to catch her breath.

“I shall take that as a compliment.” Grinning agreeably, he folded his arms across his chest.

Mercedes shook her head yet again, and shot him a scolding look that was all too fond to be intimidating. Again, he was filled with a rush of warmth that blanketed his skin in the cool night, and he couldn’t help but beam back at her.

“Well,” she began, “if you must know, I’m here to pray.”

“Oh?” his gaze rose to the stained glass windows that gleamed from the moonlight, “for victory I presume?”

“Victory?” she murmured as if the word was foreign to her, “I pray for forgiveness.”

Sylvain felt his heart still, and for a moment the two of them descended into silence. Then, he took a step back and slipped into the row behind her. As he sat, she didn’t turn to face him, gazing far away at something...  _ someone _ .

He kept his voice low and gentle, “Is this about Emile?” His name was enough to draw a trembling gasp from her, but she kept her head forward. Whether she would not, or simply could not meet his eyes, he didn’t have to see her face to know she was no longer smiling. He didn’t like that one bit. 

His hands rested on the back of her bench, just close enough to brush along her shoulders, but he kept them firmly planted at a respectable distance. He knew he should’ve protested when she begged the professor to let her join the front lines, when she laid down her arms and broke into desperate pleas for him to surrender. He definitely should have stopped her from being the one to take her brother’s life. 

“Yes and no,” she acquiesced softly, derailing his train of thoughts. Her body edged towards him ever so slightly, but she still did not face him. He did see a glimpse of dull blue eyes, and it made his guts twist painfully. Seriously, was it something he ate? What was going on with it today?

“I pray every night to the Goddess for forgiveness-” her fingers wove together as her head dips in reverence, “for every life that has been stolen by these two hands. I pray that the fallen will forgive themselves for failing their missions. Most of all, I pray that dear Emile did not die with hatred in his heart.”

Sylvain’s breath caught in his throat at the sorrow in her voice, the  _ defeat _ \- both things that he would never have associated with the gentle healer in their academy days. “It’s war, Mercedes.” he tried, “You can’t blame yourself for trying to protect those you love.”

“And yet I do.”

Biting back a bitter laugh, Sylvain merely stared at her backlit silhouette. Her shoulders were narrower than he’d remembered, and they’d been bent with the burden of war. He himself had taken countless lives over the course of the past five years, and he’d chosen to avert his eyes from the blood on his hands. As the war drew closer and closer to an end, he was beginning to realise that there was only so long he could shy away from it.

“But I suppose that’s what war is, isn’t it?” she spoke again, “ Friend against friend, blood against blood. In the end, there are only losers.”

She was right, of course. She always had been. And yet… 

“That’s war, Mercie,” he repeated softly, but the words sounded hollow even to him.

“And what a terrible thing it is.”

They lapsed into yet another bout of silence before finally, Sylvain leaned in and dropped his head on her shoulder, murmuring a quiet apology when she startled at the contact.

“Sylvain?”

“Tell me about Emile?” he asked instead.

There was a pause, and then she was telling him stories of a scrawny little boy that adored his elder sister and was terrified of cats. Mercedes laughed as she recalled a time where he burst into tears after being chased by an overtly friendly feline. Fond exasperation coloured her tone as she relayed his stubborn refusal to part with his sister for lessons. Her voice grew melodious as she repeated the songs she’d sing to him at night. 

Her voice soothed him in a way nothing else could, and for a moment he allowed himself to close his eyes and simply listen; to the way her timbre grew brighter as she spoke his name, to her giggles as she doted on his embarrassed tears, to the way her breath hitched when she described how she’d pressed a kiss to his sleeping face before she and her mother disappeared into the night.

“I suppose it was my fault then,” she mused, voice barely at a whisper, “if I had stayed- If I hadn’t-”

“Don’t.” he cut her off, “Don’t do that to yourself. If you and your mother had stayed, the both of you would be suffering at the hands of that family. You wouldn’t have been able to protect yourself, much less protect him.”

Chin lifting off her shoulder ever so slightly, he could see the way her gaze had grown faraway yet again. “He must have hated our mother. He must have hated me. We-  _ I _ \- abandoned him.”

A scarred face marred by hatred flashed in his mind's eye and he lets out a low, mirthless laugh. “Abandoned him? Hardly. You’ve always thought about him; you pleaded with him to stop with your own neck against the end of his scythe; you begged him not to hurt others for a pointless war; you never gave up on him. He knew that. If you had abandoned him, you would have turned a blind eye and denounced him as kin. If he hated you, he would have killed you all those years ago in the Holy Mausoleum.”

Sylvain very nearly jumped as soft fingers rested against his knuckles, white from how hard he was gripping the back of her bench. Instinctively, his gaze rose to meet hers- big round blues swimming with grief, pity,  _ understanding. _

_ Sheesh,  _ he thought, managing a shaky smile,  _ she really does see right through me, huh? _

Swallowing his guilt,  _ his rage _ , he let go of the bench and caught her fingers in his, giving them a light squeeze. As his gaze flickered up to meet hers, it stopped this time on her short, sandy locks.

“Why did you decide to cut your hair, anyways?” he asked, half out of genuine curiosity and half to steer away from the current subject matter.

Mercedes gave him a look, one that said she knew exactly what he was doing, but her free hand reached up to tug lightly at her ends. She graced him with a small smile, “After the monastery fell and the Blue Lions separated, Annie and I were travelling back to the School of Sorcery to see if we could rally some help. Along the way, we were ambushed by a small group of bandits.”

“Just the two of you?” Sylvain’s eyebrows shot up to his hairline, a chill shooting up his spine at the implications, “What about Ashe?”

She shook her head, “We dropped him off in House Gaspard’s territory. He insisted he escort us, but Annie and I both knew he was worried for his siblings.” An involuntary curl of her lip betrayed her fondness for the younger man, and warm as it was he still felt that same chilling unease from before. 

“‘Bandits’ is a bit of a strong word, I suppose.” she hummed, “they were more of a rag-tag band of villagers. They didn’t really know how to use their weapons, so it was an easy fight. I grew careless… A man grabbed me from behind by my hair and held his axe to my throat. Oh, if it wasn’t for Annie…”

His throat dried and a horrible rage lined the pit of his stomach, eyes resting on her unmarred neck as an involuntary sigh of relief burst from his lips. Mercedes simply let out a soft chuckle at the horror surely plain on his face, and she playfully rapped his forehead with her knuckles. “Don't scrunch up your forehead like that, the young ladies of Faerghus would weep to see the dashing heir to House Gautier sporting wrinkles at such a young age.”

It took him half a minute to process her words and finally, painstakingly smooth out his features. “While that would certainly be quite the tragedy, I’m sure you would still fall for me, right Mercie?” he punctuated his question with a wink,

“Oh Sylvain, I would fall for you even if you sprouted a second head and grew a third arm!” she swooned, to which he burst into guffaws at the grotesque image. 

“Well, I certainly hope it doesn’t come to that, but I’m glad to have one girl in my corner,” he broke into a toothy grin, propping himself on his elbows as he leaned closer.

She heaved an amused sigh, patting his head gingerly. Sylvain enjoyed that far more than he was sure he should have. 

“Anyway, the gale Annie sent his way chopped off my hair in tandem, and well, it didn’t seem practical to grow it back out given…”

_ Given the war _ went unsaid, but her plaintive shrug conveyed it just as well. 

“Well, I think you’re beautiful.” he said automatically, and he found that his words rang true- frankly, he was taken aback by his own sincerity. But it was true. Mercedes had always been devastatingly beautiful.

She too, seemed to hear the honesty in his voice, lips parting into a pretty pink “o”, before she shook her head dismissively with a soft laugh. “You do say that to everything in a skirt, but I’ll accept the flattery nonetheless.” 

His brows furrowed, “I’m not just saying it you know? I really think that it suits you.”

She gave him a disbelieving smile, unconsciously tugging on her honey-soaked locks. That didn’t sit right with him.

“Alright then, let’s make a deal,” he said, folding his arms and leaning back into his seat, “We survive this war, you let me march over to your place and give that so called father of yours a good beating- hell, since we’re in Enbarr I’ll throw in House Bartels as well- and you come live in Gautier territory. You can grow your hair out till it reaches the floor if you want.”

Mercedes simply stared at him- so much so that he was beginning to think he’d said something wrong.

“Sylvain,” she started, looking entirely too cautiously, “are you proposing to me?”

The dashing heir of the Gautier dukedom choked on his own spit, bolting upright as if he’d been electrocuted, “Goddess, no! T-that’s not what I meant- I just- I mean not to say that there’s anything wrong with marrying- any man would be lucky to- and I just- I’m not good enough for- why are you laughing?”

_ Why is she laughing?  _ he wonders.

_ She has a pretty laugh,  _ an unhelpful voice in the back of his head chips in.

_ Shut up,  _ he tells it.

Her eyes are shining as she gazes at him, pretty pink lips parted in a soft smile. Hands futilely clamped over her mouth in an attempt to muffle her chuckles, she gives him a mischievous look.

Oh, she was teasing him.

Abashed, he rubbed the back of his neck. Well, if it made her smile like that, he supposed he could handle a little bit of teasing.

“You always bully me, Mercie,” he simpered with nothing but affection in his voice and- literally what the fuck was wrong with him tonight? 

“That’s because underneath all that swagger, you’re surprisingly quite a cute person,” she beams.

Sylvain was floored, both by her bizarre word choice and his rapidly reddening cheeks.

_ Cute?  _ He thinks, dumbfounded. He parrots the word brainlessly.

“Cute,” she agreed.

He managed a boisterous laugh that came out more strangled than he’d liked, “I’ve been called handsome, charming, sexy even, but that’s definitely a first.”

She hummed, a hand finding its way into his red tresses, “Well, it’s an honour then, to be your first.” 

His eyes fluttered shut as he felt himself leaning into her touch. She gently eased his lulling head back onto her shoulder, and the saccharine scent of berries flooded his senses- the scent of spring. He breathed her in, shoulders drooping as his arms involuntarily slipped around her shoulders. She didn’t seem to mind though, lightly touching his elbow as she continued combing through his scarlet locks absentmindedly.

“I’m serious you know,” he murmured into the crook of her neck, “after this is all over, you can come back with me. I’ll give you a nice plot of land and you can do whatever you want with it- set up an orphanage, maybe a nice big garden, or even a quaint little bakery. Whatever you want. Or if you’d rather go your own way- carve your own path- I’ll support you then too.”

And he meant it. As much as the thought of Mercedes walking right out of his life twisted at his insides, he knew that more than anything, she needed to be free- of her adoptive father, whom he knew was still trying to marry her off to the highest bidder, of her brother, whose ghost would haunt her in her dreams, and most importantly, of that accursed crest that destroyed her entire life. If she wanted to walk away, change her name, completely wipe the slate clean, he would help her. Even if she was taking a piece of him with her, he would help her.

“And here I thought you wanted to marry me and make a bunch of little crest babies,” She teased, but her voice was strained. Sylvain lifted his head, brows furrowed, and his breath caught in his throat at the wetness in her gentle cornflower eyes. 

“Mercie,” he pleaded, tilting his head to brush his lips against a stray tear, “don’t cry.”

“Happy tears, Sylvain,” her voice was a little rough for wear, “they’re happy tears.” She closed her eyes and drew a shaky breath, “But why? Why would you go so far for me?”

“Because you’re important to me,” he said simply, “And you promised, right? That you would protect me?” He laid his head back on her shoulder without breaking eye contact, “Then I promise to protect you too.”

“An awful lot of promises you’re making tonight,” she whispered, voice light and tinged with a ghost of hope.

“All of which I intend to keep.”

Quietly, she rested her cheek against his crimson mop. Sylvain’s arms circled her shoulders tighter, eyelids growing heavy as he lost himself to the sweetness of berries and the soft thrum of her pulse.

“About your offer,” she murmurs, and he hums to let her know he’s listening, “bar the part where you assault my father, I think the terms are agreeable.”

His chest feels lighter and the warmth from earlier returns full force. He smiles into the crook of her neck, and this time there’s no faux pas or facades, he’s just happy. He hasn’t been that in a while.

“And what of House Bartels?” he asked, eyes still firmly closed, “They’re still up for grabs?”

“Oh, hush you-” she laughed, reaching over to flick his forehead. He doesn’t so much as flinch, merely responding with a sleepy laugh.

“Then it’s a promise?” he whispered, exhaustion finally settling over him as his breathing slowed.

“It’s a promise.” she echoed, and for the first time in months, Sylvain’s dreams weren’t plagued by bloodshed and bodies, but by the sweet waft of berries and warm touches. 

**Author's Note:**

> Thanks so much for reading Mercie bullying Sylvain for 3000 words straight!


End file.
